The present invention relates to novel 3-furyl betaoxoalkyl sulfides.
Artificial flavoring agents for foodstuffs have received increasing attention in recent years. In many areas, such food flavoring agents are preferred over natural flavoring agents at least in part because of the uniform flavor that may be so obtained. For example, natural food flavoring agents such as extracts, essences, concentrates and the like are often subject to wide variaton due to changes in the quality, type and treatment of the raw materials. Such variation can be reflected in the end product and results in unreliable flavor characteristics and uncertainty as to consumer acceptance and cost. Additionally, the presence of the natural product in the ultimate food may be undesirable because of increased tendency to spoil. This is particularly troublesome in convenience and snack food usage where such products as dips, soups, chips, prepared dinners, canned foods, sauces, gravies and the like are apt to be stored by the consumer for some time prior to use.
The fundamental problem in preparing artificial flavoring agents is that of achieving as nearly as possible a true flavor reproduction. This generally proves to be a difficult task since the mechanism for flavoring development in many foods is not understood. This is noteable in products having sweet, meaty and roasted meat flavor and nut-like flavor characteristics. It is also noteable in products having vegetable-like and hydrolyzed vegetable protein-like and anise-like flavor characteristics.
Reproduction of roasted, beef brothy, nutty, citrus and fresh lime, and sweet, meaty flavors and aromas and hydrolyzed vegetable protein-like flavors and aromas has been the subject of the long and continuing search by those engaged in the production of foodstuffs. The severe shortage of foods, especially protein foods, in many parts of the world has given rise to the need for utilizing non-meat sources of proteins and making such proteins a palatable and as meat-like as possible. Hence, materials which will closely simulate or exactly reproduce the flavor and aroma of roasted meat and sweet, meat products, vegetable products and products having nut-like taste are required.
Moreover, there are a great many meat containing or meat based foods presently distributed in a preserved form. Examples being condensed soups, dry-soup mixes, dry meat, freeze-dried or lyophilized meats, packaged gravies and the like. While these products contain meat or meat extracts, the fragrance, taste and other organoleptic factors are very often impaired by the processing operation and it is desirable to supplement or enhance the flavors of these preserved foods with versatile materials which have either roasted meat or sweet meat or vegetable-like or nut-like nuances.
U.S. Pat. No. 3,666,594 provided materials having such desirable meat, roast meat and roasted fragrance and flavor notes. Such materials are organic oxygen containing heterocyclics wherein the second carbon atom from the oxygen atom contains a sulfur substituent and included 3-thia furan compounds having the structure: ##SPC2##
wherein R.sub.6, R.sub.7, R.sub.8 and R.sub.9 are the same or different alkyl or hydrogen. The process disclosed in this patent indicated that such furan 3-thiols and alkyl substituted furan 3-thiols can be produced by the reaction of an appropriate dihydrogen furanone-3 or tetrahydro furanone-3 with hydrogen sulfide in the presence of anhydrous hydrogen chloride at temperatures of -60.degree. to -100.degree. C.
Nothing in the prior art, however, sets forth implicitly or explicitly the 3-furyl beta-oxoalkyl, sulfides of our invention and their unique and advantageous and unobvious flavor properties.
U.S. application for Pat. Ser. No. 542,830, filed on Jan. 21, 1975, discloses the use in meat flavors of 3-furyl beta oxoalkyl sulfides having the structure: ##SPC3##
where X is a chalcogen selected from the group consisting of oxygen and sulfur; R.sub.2 and R.sub.3 are each selected from the group consisting of methyl and hydrogen, at least one of R.sub.2 or R.sub.3 being methyl; and R.sub.4 and R.sub.5, taken separately, are each methyl, or R.sub.4 and R.sub.5 taken together are tetramethylene.